Talk:Hyperbolic spiral

	Hyperbolic spiral has been listed as one of the Mathematics good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Article milestones Date Process Result December 26, 2023 Good article nominee Listed A fact from this article appeared on Wikipedia's Main Page in the "Did you know?" column on January 14, 2024. The text of the entry was: Did you know ... that the spirals in photographs of spiral staircases (example pictured) are hyperbolic?

	This article is rated GA-class on Wikipedia's content assessment scale. It is of interest to multiple WikiProjects.
Mathematics Low‑priority

Hi I've replaced "Reciproke Spiral" by "Reciprocal Spiral" since it is clearly a typo. The only very few references to "Reciproke Spiral" outwith Wikipedia have clearly been copied from it. "Reciprocal Spiral" is to be much more commonly found on the internet. Mikerollem (talk) 13:05, 9 February 2022 (UTC)[reply]

This review is

transcluded from Talk:Hyperbolic spiral/GA1

. The edit link for this section can be used to add comments to the review.

Reviewer: Dedhert.Jr (talk · contribs) 12:29, 24 December 2023 (UTC)[reply]

Reviewing. Dedhert.Jr (talk) 12:29, 24 December 2023 (UTC)[reply]

Started from the lead: Why do you need to cite the fact stating it is viewed up as a spiral staircase, whereas you already cite it in the "Central projection of a helix"? Also, is it possible to put this fact in the "History and applications"?

• Ok, redundant citations removed.
• Spiral staircase added to the architecture paragraph of applications. —David Eppstein (talk) 21:26, 24 December 2023 (UTC)[reply]

History and applications: Some comments or questions regarding this section. Is there any reason not to link Polar curve, or is it just a coincidence that you forgot to put that link? Also, since the third paragraph mentions the polar equation of a hyperbolic spiral, can you put it after the section "Construction" (or "Property"), in order to make the readers understand the equation first? The hyperbolic spiral may also be applied in psychological experiments, and I wonder what are those. The link "Architecture" may not be helpful, as it is just literally the architecture, art and technique of design and building.

• Polar curve is a different concept, about algebraic curves. This is not an algebraic curve. So we're using the same phrase for an unrelated meaning and should not link the article merely because it uses the same phrase.
• "Architecture" is stated to provide context (since I don't necessarily expect readers to be familiar with the word "volute") and linked to clarify that it means building architecture not computer architecture or some other sense of the word architecture. —David Eppstein (talk) 21:26, 24 December 2023 (UTC)[reply]
• The polar equation was already stated in the lead. The choice of putting history and applications first, before the constructions, was deliberate, per
  WP:TECHNICAL (specifically called out in Good Article criterion 1a). As WP:TECHNICAL states, "it is often helpful to begin with more common and accessible subtopics, then proceed to those requiring advanced knowledge". —David Eppstein (talk) 22:53, 24 December 2023 (UTC)[reply
  ]
• Re what the psychological experiments are: "on the perception of rotation". I added a link to Psychophysics#Experimentation which appears to be the closest we have to this topic. My understand of this would be: show people spinny things and test how variations in the experiment (different shapes of spinny things, different speeds or directions of rotation) affect how strongly the people perceive the rotation. —David Eppstein (talk) 22:53, 24 December 2023 (UTC)[reply]

  @

  WP:FRINGE. Dedhert.Jr (talk) 00:56, 25 December 2023 (UTC)[reply

  ]

  My uneducated guess would be that illusions like that might be more likely to happen with Archimedean spirals. The other sort of illusion likely in this sort of setup is that the experimentor stops the spirals from spinning after a while but the subject thinks they see them spinning in the opposite direction. —David Eppstein (talk) 00:28, 26 December 2023 (UTC)[reply]

Construction: In "Cartesian coordinate", the phrase "However, one can obtain a trigonometric equation", does the word "one" count as the weasel word of pronoun, as it refers to someone, as far as I'm concerned? In the same section, do you have a link about the term "branch"? I'm asking because I think that some readers who want to understand this topic may not comprehend some mathematical terms (or some people say it jargon???). The same reason for the "image" in the phrase "the image of Archimedean spiral" in the subsection "Inversion".

• "One" is standard English phrasing used as a stand-in for a subject when there is no real subject. In more academic writing, "we" would often be used instead, but that is to a large extent discouraged on Wikipedia; see
  MOS:WE. —David Eppstein (talk) 22:58, 24 December 2023 (UTC)[reply
  ]
• We don't seem to have a good article about the word "branch" as used here (and in the sources here). Principal branch and branch point are related, but different enough that they would be more confusing than helpful to link. The closest is wikt:branch but it's still not very helpful. —David Eppstein (talk) 23:05, 24 December 2023 (UTC)[reply]
• We do, however, have a good link for image: Image (mathematics). Added. —David Eppstein (talk) 23:06, 24 December 2023 (UTC)[reply]

That's odd. For some reason, in this article [2] it is categorized as weasel word. I have no idea why, but nevermind. Dedhert.Jr (talk) 00:49, 25 December 2023 (UTC)[reply]

I think the suggestion that it is weasel wording there is more related to the handwavy "one can thus conclude" reasoning than to the grammar. —David Eppstein (talk) 00:29, 26 December 2023 (UTC)[reply]

Properties: Just asking here. Do you need the formula ${\displaystyle r=r(\varphi )}$ in the "Curvature"? From my perspective, it may cause some confusion with the unfamiliar technical symbols. Nevermind, I didn't see that it represents a function, which may be used for its derivatives applying in the formula. For the "Arc length", I do think that the vdots may be useless for portraiting them to the readers, and maybe some calculations can be simplified and spit out the results; do you actually need it?

• Ok, removed several intermediate formulas (including the extra dots) and added a little more text explaining the formulas. —David Eppstein (talk) 23:23, 24 December 2023 (UTC)[reply]

The article is well-written, with some kind of technical terms that may need attention (GACR#1a). I believe there is no original research in this article; every section is filled with reliable sources but with some little copyvio here (GACR2) The article is broad in its coverage (GACR3). Neutral and no edit war (GACR4 and GACR5). The article has pictures or images illustrating the text in every paragraph, together with the captions (GACR6).

I think that's all for today. If you have any questions or complete all of these tasks, please ping me, and I may respond swiftly. If there is something wrong with my suggestions, please warn me and I will try to understand more. Thank you Dedhert.Jr (talk) 13:17, 24 December 2023 (UTC)[reply]

@David Eppstein Okay. I think all of the suggestions have completed. Passing the nomination! Congrats! By the way, if anyone has proposal to add some improvement, just ask in the talk page. Dedhert.Jr (talk) 03:01, 26 December 2023 (UTC)[reply]

Of course! Passing GA should not mean an end to the improvement; it will stay on my watchlist. And thanks again for the review! —David Eppstein (talk) 03:04, 26 December 2023 (UTC)[reply]

No problem. Just my first time passing. Dedhert.Jr (talk) 03:21, 26 December 2023 (UTC)[reply]

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by Bruxton talk 15:07, 7 January 2024 (UTC)[reply]

(

• Comment or view
• Article history

)

The spirals in this photo of a spiral stair are hyperbolic

• ... that the spirals in photos of spiral staircases (pictured) are hyperbolic? Source: Hammer, https://doi.org/10.1007%2F978-3-319-47373-4_15 (paywalled)
  • ALT1: ... that the starting blocks of 200m and 400m footraces are positioned along hyperbolic spirals? Source: Haines, https://www.jstor.org/stable/3617399 (paywalled but probably available through The Wikipedia Library)
  • Reviewed: Template:Did you know nominations/Hank Aaron State Trail and Template:Did you know nominations/California mission project (double QPQ for heavy backlog)

Improved to Good Article status by David Eppstein (talk). Self-nominated at 03:57, 26 December 2023 (UTC). Post-promotion hook changes for this nom will be logged at Template talk:Did you know nominations/Hyperbolic spiral; consider watching this nomination, if it is successful, until the hook appears on the Main Page.[reply]

• Date, size, hooks, copyvio spotcheck, etc. all GTG. --_{Piotr Konieczny aka Prokonsul Piotrus| reply here} 12:03, 2 January 2024 (UTC)[reply]

@David Eppstein: AGF on the sources for the hook. ALT0 works with the article and it an interesting image. I am removing the link to staircases so that people do not click on it instead of the article. Also I added the staircase location to the image at commons. Bruxton (talk) 15:05, 7 January 2024 (UTC)[reply]

I think there must be a mistake in the mathematical specifications as the paragraph is not wrapping properly around the information box. Same results in Chrome and Edge. Sorry I don't know how to amend this -- could someone have a look at it please? It's the paragraph starting "As a

Thank you DavidCh0 (talk) 18:21, 24 January 2024 (UTC)[reply]

@DavidCh0 I tried adding a paragraph break in that paragraph. Did that fix your issue? –jacobolus (t) 19:07, 24 January 2024 (UTC)[reply]

Thank you - it's made some difference but it is still not right. I tried taking "scale factor" out of the [[]] and at least it didn't break the word "factor", but I'm outside my comfort zone so don't want to experiment in a way that might affect other views. DavidCh0 (talk) 15:39, 25 January 2024 (UTC)[reply]

Further experimentation leads me to think that the illustrations need to be sited next to paragraph(s) without mathematical codes (I noticed the same problem further down). Again I'd rather leave it to a more experienced editor... DavidCh0 (talk) 15:52, 25 January 2024 (UTC)[reply]

This is a strange rendering bug. I can't reproduce it here in any browser at any viewport width. Maybe you want to start a bug report in the mediawiki bug tracker https://phabricator.wikimedia.org and share information about your browser/etc. –jacobolus (t) 17:06, 25 January 2024 (UTC)[reply]

I made a sandbox page at Talk:Hyperbolic spiral/sandbox which you are welcome to fiddle with. I switched from <math display=block>... to :<math>... which I am guessing will fix your issue, but I wonder what the actual problem is. There's clearly some kind of interaction with the display=block used in a paragraph, but I don't get why your browser is treating it quite so wonky – the pattern of putting display=block in a paragraph causes the content following the math tag to be included as a "bare" text node, not inside any top-level block element. –jacobolus (t) 17:12, 25 January 2024 (UTC)[reply]